Refrigerating system



Dec. 29, 1936.

H. M. GRAHAM REFRIGERATING SYSTEM Filed Feb. 24, 1932 2 Sheets-Sheet 1 A TTORNEYS Dec. 29, 1936. H. M. GRAHAM REFRIGERATING SYSTEM 2 sheets-sheet 2 Filed Feb. 24, 1932 pov/M42 A TTORNEYS Patented Dec. 29, 1936 UNITED STATES PATENT OFFICE REFRIGERATING SYSTEM Harold M. Graham, Buialo, N. Y., assignor to Ross Heater & Mfg.

. Inc., Buffalo, N. Y., a

This invention relates to improvements in refrigerating systems of the kind in which the required low temperature of the cooling medium is obtained by causing it to iiow through a cooling chamber in which a relatively high vacuum is maintained and more particularly the invention is concerned with such a system in which the vacuum is maintained by steam ejectors.

Systems of the type generally described, as heretofore proposed, require such large quantities of cooling water for the condensers which are employed in connection with the steam ejectors as to render this mode of cooling relatively expensive owing to the cost of cooling the water in those systems in which it is recirculated or because of pumping charges in those installations in which the quantity of water employed is of little importance.

The principal object of the present invention is to provide a system wherein the quantity of cooling water required to condense the steam from the ejectors is substantially less than that required in systems as heretofore proposed, this object contemplating a novel arrangement of the condensers and ejectors.

The invention has features which render it of particular utility in connection with water cooling systems such, for example, as are employed in hotels and o'ice buildings, and the invention is described in this connection. It is to be understood, however, that this is by way of example only as the invention is equally applicable to the cooling of other liquids.

The invention is illustrated in the accompanying drawings, in which:

Figure 1 is a diagrammatic View of a liquid cooling system embodying features of the invention.

Figure 2 is a similar view illustrating the ap-4 a suitable shell 5 which provides a cooling cham- ,i

ber 5a. The liquid to be cooled is delivered to the cooling chamber through a pipe 6, the latter being connected to a pipe I which is arranged within the cooling chamber and which is suitably apertured so that the liquid is discharged therefrom in the form of sprays 8. The liquid is cooled in the chamber 5a in the manner to be described. It may be. withdrawn from the cooling chamber through a pipe 9 by means of a pump I0 and employed in any manner desired. For example, it may be conducted to drinking fountains or it may be circulated through cooling coils as a refrigerating medium. The pipe 6 includes a suitable valve II which is i controlled by a oat I2 Within the evaporating chamber. The oat serves to maintain a predetermined quantity of liquid in the cooling chamber, it being understood that the liquid which is delivered through the pipe 6 may be either from an outside source of supply or it may be the same liquid withdrawn from the cooling chamber but which by virtue of its use has been heated to a temperature such that its recooling is necessary.

The required temperature of the liquid in the cooling chamber is obtained by maintaining ay relatively high vacuum in the cooling chamber,

that is to say an absolute pressure in the order of .25 inch of mercury. The pressure desired is obtained by steam ejectors I3 and III which are provided with nozzles I5 and I6 respectively. The nozzles I5 and I6 are connected to a coinmon steam supply pipe I1. By virtue of the vacuum which is maintained in the' cooling chamber the liquid which enters the chamber is cooled', it being understood, of course, that a portion of the liquid vaporizes. The temperature of the liquid depends upon the degree of vacuum maintained in the chamber. Hence, by controlling the supply of steam to the nozzles I5 and I 6 the temperature of the liquid is lowered to the desired value. To this end the steam supply pipe I1 includes a valve I8. The latter is controlled by a thermostat I9 which is immersed in the liquid in the cooling chamber. The thermostat is operable to control the flow of steam to the nozzles I5 and I6 -in accordance with the. temperature of the liquid. Hence, if the temperature of the liquid is higher than the predetermined temperature the valve-I8 automatically opens to increase the supply of steam to the nozzles whereas when the temperatureI of the liquid is lower than the predetermined value, the valve automatically closes to reduce the ow of steam to the nozzles. The steam from the ejector I5.is discharged into a pipe 20' while the steam from the ejector I6 is discharged into a pipe 2I. The pipes 20 and 2| communicate with condensers 22 and 23 respectively of conventional construction. It will be apparent, therefore, that the vaporized liquid from the cooling chamber and the steam from the ejectors is discharged into the condensers, it being understood, of course, that the steam and vaporized liquid are compressed so that their condensation condensers is facilitated.

Means is provided for maintaining the conin the densing chambers of the condensers 22 and 23 under a relatively high vacuum. The said means includes evacuators 23a and 24, each of which is in communication with the condensing chamber of its respective condenser through a pipe 25. Any uncondensed vapor in the condensing chambers is withdrawn through the pipes 25 by steam ejectors 26, the latter being in communication with a source of steam through pipes 21. The vapor withdrawn from the condensers is discharged into the inlet chambers 28 of auxiliary condensers 29, the inlet chambersbeing separated from outlet chambers 30 by partitions 3I. The auxiliary condensers are provided with conventional cooling tubes which are arranged in the chambers 28 and 30 and the cooling medium is circulated through the condensers by suitable inlet and outletl connections 32.

The uncondensable vapors are withdrawn from the inlet chambers 28 by ejectors 33 which are in communication with the source of steam, the steam from the ejectors 33 and the uncondensable vapors from the chambers 28 being discharged into the outlet chambers 3ll of the condensers. The said chambers are in communication with the atmosphere through outlet connections 34 and any remaining uncondensable vapors are discharged through the connections into the atmosphere. The condensate from the condensers 22 and 23 is withdrawn through pipes 35 by suitable pumps 36 and disposed oi.' in any convenient manner.

The condensers 22 and 23 are of conventional construction and each includes an inlet connection 31 and an outlet connection 38. In accordance-with the invention the outlet connection 38 of the condenser 22 is connected to the inlet connection 31 of the? condenser 23, whereby the said condensers are connected in series by a suitable pipe 39. It will be apparent, therefore, that the water which is delivered to the condenser 22 through the inlet connection 31 passes from the condenser through the outlet 38 and is conducted by the pipe 38 to the condenser 23. From the latter it is discharged through the outlet connection 38. It is understood, of course, that the outlet connection 38 of the condenser 23 and the inlet connection 31 of the condenser 22 may bel connected in a closed circuit which includes a cooling tower or other suitable cooling means if it is desired that the cooling water for the condensers be re-used or instead of recirculating the water through the condensers in this manner fresh water may be delivered continuously to the.

and be discharged continuously condenser 2I from the outlet connection 38 if conservation of the cooling water is unnecessary.

From the foregoing it will be apparent that the cooling water in the condenser 22 is heated only by the steam from the ejector I5 while the cooling water in the condenser 23 is further heated by the steam from the ejector I6. In other words, the .temperature of the cooling water in the condenser 23 is higher than that in the condenser 22. Owing principally to the higher temperature of the cooling water in the condenser 23, the vacuum in the latter is lower than that in the condenser 22. For example, if 'the absolute pressure in the condenser 22 is of the orden of 2 inches of mercury then the absoluteV 2| to the extent necessary to insure its condensation in the condenser 23.

From the foregoing it will be apparent that the connection of the condensers 22 and 23 in the manner described enable maintenance of the desired vacuum in the cooling chamber, the passage of the cooling water from the condenser 22 in which a relatively high vacuum is malntained to the condenser 23 in which a relatively lower vacuum is lmaintained enabling condensation of the steam from the ejectors I3 and I4 with a minimum consumption of cooling water. The system, therefore, has the advantage that it is economical to operate and eliminates the necessity of large cooling towers when it is desired that the water for the condensers be caused to flow in a. closed circuit. A further advantage obtained is that in those installations in which the conservation of water is not essential as, for example, when the installation is near a body of water, pumping charges are minimized.

In the embodiment shown in Figurev 2 the invention is illustrated in connection with a liquid cooling system in which the cooling of the cooling medium is effected in stages. The system, therefore, includes shells 40 and 4I which provide cooling chambers 40a and 4Ia respectively. 'I'he liquid to be cooled is delivered to the cooling chamber 4Il'a through a pipe 42, the liquid being introduced in -the form of a spray as described in connection with Figure 1. 'I'he liquid is cooled in the chamber 40a to a. predetermined degree in the manner to be described and flows from the shell 40 through a pipe 43 to the cooling chamber 4Ia. In the latter the temperature of the liquid is lowered further to a predetermined degree and it may be withdrawn therefrom by a pump 44 and conducted by a pipe 45 to the point where it is to be availed of in its cooling capacity. The pipes 42 and 45 may be included in a closed circuit so that the cooling medium is recirculated through the system or the liquid which is withdrawn from the cooling chambers may be suitably disposed of after its use without being returned to the cooling chambers.

The cooling of the liquid in the cooling chamber 40a is effected by an ejector 46 to which steam is supplied from a convenient source through a pipe 41. The ejector 46 creates a vacuum inthe cooling chamber which may be, for example, an absolute pressure of the order of .36 inch of mercury, thereby cooling the liquid to a predetermined degree. For example, if the liquid is water it will be cooled to a temperature of the order of 50 F. The steam from the ejector 46 together with the vaporized liquid from the cooling chamber is compressed in a pipe 48 and discharged into a condenser 43. A relatively high vacuum is maintained in the latter by a suitable evacuator 5I) similar to the evacuators disclosed in Figure 1. The condensate from the condenser 49 is withdrawn through a pipe 5I by a pump 52 and conducted to a couvenient point of disposal.

The second stage of cooling which is can'ied out in the cooling chamber 41a is effected by an ejector 53, the latter being supplied with steam from the source of supply through a pipe 54. 'Ihe vacuum maintained in the cooling chamber 4Ia is higher than that maintained in the cooling chamber 46a. For example, it may be an absolute pressureof the order of .25 inch of mercury. Hence, if the cooling medium is water its temperature will be lowered to approximately F. The water, therefore, which is withdrawn from the cooling chamber 4Ia will be of this temperature.

The steam from the ejector 53 together with the vaporized liquid from the chamber 41a is compressed and conducted by a pipe 55 to a condenser 56 which is similar to the condenser 49. A relatively high vacuum is maintained in the condenser 56 by an evacuator 51 and the condensate from the condenser is withdrawn by a pump 58 in a manner similar to that described in connection with the condenser 49.

The condensers 56 and 49 are provided with conventional inlet andoutlet connections 59 and 60 respectively and in accordance with the invention the outlet 60 of the condenser 56 is connected by a pipe- 6I to the inlet 59 of the condenser 49. Hence, the cooling mediumwhich is delivered to the condenser 5B through the inlet 62 rst passes through the tubes of the con'- denser and is then conducted by the pipe 6I to the condenser 49, it being understood that the coolingv water is rst heated in the condenser 56 and then further heated in the condenser 49. As described in connection with Figure 1, the water discharged from the condenser 49 may be cooled in any suitable manner and then returned to the inlet of the condenser 56 or the cooling water discharged'through the outlet 60 of the condenser 49 may be disposed of in any convenient manner. Owing to the relatively higher temperature of the cooling water delivered to the condenser 49 the vacuum which is maintainul in the latter will be correspondingly lower. For example, if an absolute pressure of the order of 2 inches of mercury is maintained in the condenser 56 then the absolute pressure maintained in the condenser 49 will be of the order of 2.5 inches of mercury. Hence, steam is delivered to the ejector 46 at a higher rate than to the ejector 53 in order to compensate for the higher temperature of the coolingwater 1n the condenser 49 and insure condensation of the steam and vaporized liquid discharged into the latter.

other.v During its passage through the condensers, the temperature of the cooling water is progressively increased and the delivery of the steam to the ejectors is so regulated that the steam is delivered to the ejectors in accordance with the temperature of the cooling water in the condensers. In other words, in a .condenser in which the temperature of the cooling water is relatively high the rate at which the steam is delivered to the ejector is correspondingly high. In each of the embodiments illustrated two condensers are shown and an ejector is employed in connection with each of the condensers. It is to b'e understood, however, that this is by way of example only as the number of condensers, the number of ejectors and the number of ejectors relative to the number of condensers may be varied to meet dilerent requirements.

`If desired the condensers may be constructed in a vsingle unit, the invention contemplating any arrangement wherein the cooling tubes of the condensing chambers are connected in series.

I claim as my invention:

In a refrigerating system, the combination with a cooling chamber through which a cooling medium is caused to circulate, of a plurality of steam ejectors for maintaining a vacuum in said chamber, whereby the temperature of the cooling medium is lowered to a predetermined value, a condensing chamber into which one of said ejectors discharges, a second condensing chamber into which a second of said ejectors discharges,

means for maintaining a vacuum in said condensmg chambers, means for connecting the cooling tubes of said condensing chambers inv series so that the cooling water is caused to flow from said rst mentioned condensing chamber to said second condensing chamber, the temperature of the cooling. water being progressively raised as it passes through said condensing chambers, the nozzle of said second'ejector being so formed that steam passes through it at a higher rate than through the nozzle of said rst mentioned ejector, whereby to compensate for the lower vacuum maintained in said second condenser, a common supply pipe ,for the said ejectors, a valve in said pipe and means responsive to the temperature of the cooling medium in "said cooling chamber for automatically regulating said valve to control the supply of steam to the nozzles of said ejectors in accordance with the temperature of said cooling medium.

HAROLD M. GRAHAM. 

